摘要
为探究高速铁路预应力混凝土矮塔斜拉桥运营阶段收缩徐变效应规律,依托新建京沈高铁潮白河特大桥工程,借助有限元方法,以成桥阶段为基准,分析运营3个月至30年等时间段后,收缩徐变引起结构主要构件的变形和受力变化规律。研究表明:(1)收缩徐变引起主跨主梁下挠,有斜拉索锚固的边跨主梁上拱,无斜拉索锚固的边跨主梁下挠,桥塔有向主跨跨中方向变形的趋势;(2)收缩徐变作用下,主梁截面上下缘应力变化规律不同,塔柱和斜拉索内力均减小;(3)收缩徐变对结构变形和受力的影响呈现早期大、后期小和早期快、后期慢的规律,运营3年后,收缩徐变引起的结构变形和受力变化完成约80%,运营5年后,收缩徐变对结构的变形和受力几乎无影响;(4)非对称施工使结构运营期间的收缩徐变最大变形减小约20%,对结构后期运营无不利影响。
In order to understand the law of shrinkage and creep effect of prestressed concrete low tower cable-stayed bridge in operation stage on high-speed railway,relying on the newly-built Chao-Bai River Bridge of Beijing-Shenyang Railway,taking the completion stage as the benchmark,the deformation and stress’s variation law of main structural components after operation for 3 months to 30 years are analyzed with finite element method.The following conclusions are drawn:(1)Under the influence of shrinkage and creep,the main span’s main girder will deflect downward,the side span’s main girder with stay cable anchorage will arch upward,and the side span’s main girder without stay cable anchorage will deflect downward,and the bridge tower will deform towards the middle of the main span;(2)Under the action of shrinkage and creep,the stress at the upper and lower edges of the main beam section increases or decreases,and the internal forces of the tower column and stay cable decrease;(3)The influence of shrinkage and creep on the deformation and stress of the structure shows the law of large in the early stage,small in the later stage,rapid change in the early stage and slow change in the later stage,and the change of structural deformation and stress caused by shrinkage and creep has been completed by about 80%after 3 years of operation,and shrinkage and creep has little effect on structural deformation and stress after 5 years of operation.(4)Compared with the construction according to the original design steps,the asymmetric construction reduces the maximum deformation of shrinkage and creep during the operation of the structure by about 20%,which has no adverse impact on the later operation of the structure.
作者
胡豪
施洲
Hu Hao;Shi Zhou(China Railway Engineering Design and Consulting Group Co.,Ltd.,Beijing 100055,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《铁道勘察》
2022年第6期128-133,共6页
Railway Investigation and Surveying
基金
中国铁路总公司科技开发计划项目重大课题(2017G006-A)
关键词
高速铁路
矮塔斜拉桥
预应力混凝土
收缩
徐变
有限元法
high-speed railway
low tower cable-stayed bridge
prestressed concrete
shrinkage
creep
finite element method
作者简介
胡豪(1993—),2020年毕业于西南交通大学桥梁与隧道工程专业,工学硕士,助理工程师,E-mail:huhao312@126.com。
